#pragma semicolon 1
#pragma newdecls required

#include <sdktools>
#include <sdkhooks>

#define MAX_LIST 18

Handle sdkSetAttack;

static const char gWeapons[MAX_LIST][] =
{
    "weapon_autoshotgun",
    "weapon_hunting_rifle",
    "weapon_pistol",
    "weapon_pistol_magnum",
    "weapon_pumpshotgun",
    "weapon_rifle",
    "weapon_rifle_ak47",
    "weapon_rifle_desert",
    "weapon_rifle_m60",
    "weapon_rifle_sg552",
    "weapon_shotgun_chrome",
    "weapon_shotgun_spas",
    "weapon_smg",
    "weapon_smg_mp5",
    "weapon_smg_silenced",
    "weapon_sniper_awp",
    "weapon_sniper_military",
    "weapon_sniper_scout"
};

static const float gDistance[MAX_LIST] =
{
    1650.0,
    1100.0,
    880.0,
    1980.0,
    1650.0,
    1100.0,
    1100.0,
    1100.0,
    1320.0,
    1100.0,
    1540.0,
    1540.0,
    880.0,
    880.0,
    880.0,
    1870.0,
    1320.0,
    1320.0
};

public void OnPluginStart()
{
    HookEvent("weapon_fire", EventFire);

    Handle hGameConf = LoadGameConfigFile("added_sound-attracts-zombies");
    StartPrepSDKCall(SDKCall_Entity);
    if( PrepSDKCall_SetFromConf(hGameConf, SDKConf_Signature, "SetAttackToSurvivors") == false )
        SetFailState("Could not load the \"SetAttackToSurvivors\" gamedata signature.");
    sdkSetAttack = EndPrepSDKCall();
    delete hGameConf;
}

public Action EventFire(Handle event, const char[] name, bool dontbroadcast)
{
    int client = GetClientOfUserId(GetEventInt(event, "userid"));
    if(bIsSurvivor(client))
    {
        int weapon = GetEntPropEnt(client, Prop_Send, "m_hActiveWeapon");
        if(IsValidEntity(weapon))
        {
            char weaponname[36];
            GetEntityClassname(weapon, weaponname, sizeof(weaponname));

            float vPos[3], vTargetPos[3];
            GetClientEyePosition(client, vPos);

            for( int i = 0; i < MAX_LIST; i++ )
            {
                if(strcmp(weaponname, gWeapons[i]) == 0)
                {
                    int entity = -1;
                    while( (entity = FindEntityByClassname(entity, "infected")) != INVALID_ENT_REFERENCE )
                    {
                        GetEntPropVector(entity, Prop_Send, "m_vecOrigin", vTargetPos);
                        float fTargetDistance = GetVectorDistance(vPos, vTargetPos);

                        if(IsVisibleTo(vPos, vTargetPos))
                        {
                            if(fTargetDistance < gDistance[i])
                            {
                                SDKCall(sdkSetAttack, entity);
                            }
                        }
                        else
                        {
                            float iOne = gDistance[i] / 3;
                            int vForward = RoundToCeil(gDistance[i] / iOne);
                            int vTotal = 50 / (vForward * vForward * vForward);
                            if(GetRandomInt(0, 100) <= vTotal)
                            {
                                if(fTargetDistance < iOne)
                                {
                                    SDKCall(sdkSetAttack, entity);
                                }
                            }
                        }
                    }
                    break;
                }
            }
        }
    }
}

static bool IsVisibleTo(float position[3], float targetposition[3])
{
    float vAngles[3], vLookAt[3];

    MakeVectorFromPoints(position, targetposition, vLookAt);
    GetVectorAngles(vLookAt, vAngles);

    Handle trace = TR_TraceRayFilterEx(position, vAngles, MASK_SHOT, RayType_Infinite, _TraceFilter);

    bool isVisible = false;
    if (TR_DidHit(trace))
    {
        float vStart[3];
        TR_GetEndPosition(vStart, trace);

        if ((GetVectorDistance(position, vStart, false) + 25.0) >= GetVectorDistance(position, targetposition))
        {
            isVisible = true;
        }
    }

    delete trace;
    return isVisible;
}

public bool _TraceFilter(int entity, int contentsMask)
{
    if (IsValidEntity(entity))
    {
        return false;
    }
    return true;
}

stock bool bIsSurvivor(int client)
{
    return client > 0 && client <= MaxClients && IsClientInGame(client) && GetClientTeam(client) == 2 && !IsClientInKickQueue(client) && IsPlayerAlive(client);
}